APO 16 (21 August 2009)
This decision1 reminds us that if you want to extend an Australian pharmaceutical patent, you must first make sure that your claims are in good order. Specifically, you must be certain that the claim on which your extension is to be based is one that is directed to a ‘pharmaceutical substance per se’.
Importantly, while the Australian Patent Office is now of the view that a pharmaceutical substance ‘can include a compound with a controlled spatial configuration if, as a whole, it can still be considered a pharmaceutical ‘substance’ ‘(see N. V Organon  APO 8 ) it is clear from this decision that the longer held view ‘the combination of such a substance with what would reasonably be considered a separate physical device, layer or structure……..is excluded and indeed would not be a ‘pharmaceutical substance per se’ still applies.
In this case, there was no argument as to whether the matrix layer including rotigotine free base and a polymeric adhesive substance of the relevant claim was a ‘pharmaceutical substance per se’. The question was whether, because the claim included other components in the form of an inert backing layer and a protective layer, the relevant claim is directed to a substance that as a whole is a pharmaceutical substance per se.
In answering this question, the Commissioner made it quite clear that the inclusion of the backing and protective layers in the relevant claim would not be fatal to the extension ‘if the patentee could demonstrate that the product as a whole shows a level of integration or interaction between the component parts’. Unfortunately, the patentee was not assisted by submissions made during the prosecution of the extension application that the backing and protective layers ‘in no way contribute to the working of the therapeutic substance’.
Taking a step back, it becomes clear that the problem has arisen either because:
- without the backing and protective layer features, a claim directed to the matrix layer per se could not have been allowed, or otherwise
- prior to allowance, the impact of these claimed features on patent term extension had not been fully understood.
Generally, under Australian law, claim amendments made post allowance must narrow the claim scope. Given this, one must remember that the time to make sure that claims are in good order for patent term extension is not after grant, but prior to allowance.